Crane mast according to its different material, can be divided into wooden mast and metal mast. The mast can be divided into a single foot, hermit and tripod three. The metal mast can be divided into steel pipe type and structural type. According to the surname, the structure can be divided into: hermitage mast, traction mast, gantry mast.
The gin mast, also known as the derrick, is a commonly used lifting gear. It works with winch, pulley block and rope for lifting operation. It is widely used in the installation of equipment and large components due to its simple structure, easy installation and removal, low requirements for installation site and strong adaptability.
The derrick is a post - type mast and is taut to the ground with a rope (cabling). The taut end is fastened to the top of the gin mast. The other end is fixed on the ground anchor pile. Generally not less than three cables, usually 4-6. The initial tension of each cable is about 10-20kN and the cable is at an Angle of 30-45 degrees with the ground. The included Angle of each cable on the horizontal projection plane should not be more than 120 degrees.
The gin mast may stand upright or lean to the ground (usually at an Angle not less than 80 degrees). The derrick is backed with a pillowcase. A pulley block on the top of the gin mast for lifting heavy objects. The rope is drawn from the pulley block and guided to the winch through the lower mast guide pulley.
Requirements:
1. When assembling the new mast, the centerline deviation shall not be greater than 1/1000 of the total supporting length;
2. When reassembling masts that have been used many times, the centerline deviation and local plastic deformation should not be greater than 20 mm per 5 m of length;
3. Within the full length of the mast, the center deviation should not be greater than 1/200 of the total supporting length;
4. The connecting bolts for the mast assembly must be firmly fastened;
5. The foundation of all masts must be smooth and firm without water.
